自动分离提纯系统的研制及其在同位素分析测试中的应用

传统自然流速层析柱法存在离子容易扩散、流速不可控等问题,而元素的自动分离提纯技术可以提高同位素分析效率,压缩在室内提纯化学元素所需的时间。为了降低这种扩散效应、缩短淋洗时间,本文研制了一种自动分离提纯系统,用于元素的自动分离、提纯。该系统由流体切换阀、柱塞泵、自动进样器等部件构成,所有部件与计算机联接,每个部件可单独控制。该系统装配了两根层析柱,通过控制切换阀,可使两者组合使用,甚至能进行逆向淋洗,这与传统自然流速法完全不同。将海水样品分别通过传统自然流速法和本系统进行淋洗提纯,使用加压自动分离提纯系统后,元素(尤其是阴离子)的扩散效应得到明显改善。上样量均为1.0mL时,采用传统自然流速法,硼元素的淋洗峰宽为2.5～3.0mL,而采用本系统淋洗峰宽仅为1.0mL。自然流速法下,不同酸度淋洗液的淋洗速度不同,而本系统的流速精确可控,可确保流速稳定。本文研制的自动分离提纯系统在分离效果和分离能力上均比传统重力法表现优异,在分离元素进行同位素分析方面具有较大的应用前景。

A Fully Automated Chemical Separation and Purification System and Its Application to Isotope Analysis

BACKGROUND: Critical problems such as ion diffusion and uncontrollable flow rate exist when applying the traditional natural flow chromatography column method to isotope analysis. The proposed automated chemical purification system improves the efficiency of isotope analysis, and reduces the time required for element purification.
OBJECTIVES: To develop an automated chemical separation and purification system.
METHODS: The automated chemical separation and purification system was composed of multi-way valves, plunger pump, autosampler, etc. All of the components were connected using a computer and each of them can be controlled independently. By combining two chromatographic columns multiple functions can be achieved, including reversed elution, which cannot be achieved by the traditional natural flow chromatography column method. In order to investigate the performance of the automated chemical separation and purification system, fresh seawater was purified with the proposed system and the traditional method simultaneously.
RESULTS: The elution peak of boron had a width of 2.5mL to 3.0mL for the traditional method, but only ca. 1.0mL for the proposed system, if the loading volume of seawater was 1.0mL. The flow rate of the elution depended on the acidity using the traditional natural flow chromatography column method. However, the flow rate could be strictly controlled with the automated chemical separation and purification system.
CONCLUSIONS: The precisely controlled flow rate of the system makes an easier prediction of the elution time and elution peak. The reversed column technology of the system can be applied to the separation and purification of elements for isotope analysis.